By comparing it to something Bionicle-related, I assumed you were referring to the reaction on BZPower. I don't doubt that some people elsewhere are making a fuss over it, though.

But we did have people threatening to fly to Denmark and kill themselves to make a point when Bionicle ended, soo..

At any rate, yeah, Derpy was a minor character and the show (and fandom) will go on without her, but she was one of its most endearing elements. One of Hasbro's biggest nods to the fanbase, and kind of a staple of the show overall, even as a background character.

I think the issue is that the fans got one of the biggest acknowledgments so far from the crew in the form of Derpy, and then it got taken away. Yes, people overreacted, but even for a casual fan like me it stung to see this whole issue take place. Of course, the overreaction of the bronies didn't help; in fact, it was more like rubbing salt in a wound. Nothing like seeing a fandom that claimed to be founded in love and tolerance making declarations of hatred and rage.